U.S. patent number 5,470,648 [Application Number 08/258,120] was granted by the patent office on 1995-11-28 for composite fabrics of nonwoven nylon layers and fiberglass scrim.
This patent grant is currently assigned to E. I. Du Pont de Nemours and Company. Invention is credited to Vijayendra Kumar, Paul S. Pearlman.
United States Patent |
5,470,648 |
Pearlman , et al. |
November 28, 1995 |
Composite fabrics of nonwoven nylon layers and fiberglass scrim
Abstract
This invention relates to composite fabrics having two layers of
nonwoven fabric comprising entangled non-bonded nylon filaments and
a reinforcing layer of fiberglass scrim adhesively attached to each
of the nonwoven layers. The composite fabrics are useful as
backings in a carpet assembly.
Inventors: |
Pearlman; Paul S. (Thornton,
PA), Kumar; Vijayendra (New Castle, DE) |
Assignee: |
E. I. Du Pont de Nemours and
Company (Wilmington, DE)
|
Family
ID: |
27170592 |
Appl.
No.: |
08/258,120 |
Filed: |
June 10, 1994 |
Current U.S.
Class: |
442/26 |
Current CPC
Class: |
B32B
5/26 (20130101); D04H 1/4334 (20130101); D04H
1/593 (20130101); D04H 3/004 (20130101); B32B
5/06 (20130101); D04H 3/011 (20130101); D04H
3/04 (20130101); B32B 5/022 (20130101); D04H
3/009 (20130101); Y10T 442/143 (20150401); B32B
2262/0261 (20130101); B32B 2262/101 (20130101) |
Current International
Class: |
B32B
5/26 (20060101); B32B 5/22 (20060101); D04H
13/00 (20060101); B32B 005/12 () |
Field of
Search: |
;428/224,225,229,246,247,284,296 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Ryan; Patrick J.
Assistant Examiner: Weisberger; Richard P.
Claims
We claim:
1. A composite fabric, comprising:
a) a first layer of a nonwoven fabric comprising entangled,
non-bonded nylon filaments;
b) a second layer of fiberglass scrim comprising an array of
intersecting continuous multifilament glass strands; and
c) a third layer of a nonwoven fabric comprising entangled,
non-bonded nylon filaments, wherein each layer of nonwoven fabric
is adhesively attached to the layer of fiberglass scrim at a
contact surface along said fabrics and scrim in such a manner that
individual nylon filaments within the first and third layers of
nonwoven fabric are mobile between the strands in the scrim.
2. The composite fabric of claim 1, wherein the fiberglass scrim
comprises an intersecting array of at least 6 multifilament strands
by 6 multifilament strands per inch of scrim.
3. The composite fabric of claim 2, wherein each multifilament
strand has a denier of at least 500 and a tensile break strength of
at least 8 pounds.
4. The composite fabric of claim 2, wherein the fiberglass scrim
further comprises multifilament glass strands crossing over the
intersecting array of multifilament strands in a diagonal
direction.
5. The composite fabric of claim 1, wherein the nylon filaments of
each nonwoven layer of nylon fabric are hydro-entangled or
needle-punched.
6. The composite fabric of claim 5, wherein the nylon filaments are
continuous filaments or staple fiber.
7. The composite fabric of claim 1, wherein the adhesive is a
modified acrylic resin.
Description
FIELD OF THE INVENTION
This invention relates to composite fabrics having two layers of
nonwoven fabric comprising entangled, non-bonded nylon filaments
and a reinforcing layer of glass fiber scrim.
BACKGROUND OF THE INVENTION
Nonwoven fabrics composed of nylon fibers may be used for
manufacturing such products as hospital gowns, wiping cloths, and
home furnishings such as sheets, table cloths, carpets, and rugs.
However, in some environments where there are seasonal changes in
the humidity and temperature, these fabrics are liable to become
distorted due to shrinkage and expansion of the fabric. In the case
of rugs or carpets that are loosely laid and then held to the floor
at spaced locations by heavy furniture or the like, seasonal
weather changes may produce such distortions that result in
buckling of the carpet surface between stationary portions of the
carpet. This carpet buckling is unsightly and presents a tripping
hazard. In view of the foregoing, there is a need for a nylon
nonwoven fabric which would demonstrate good strength and moisture
stability under common environmental conditions.
The present invention provides a composite fabric comprising two
layers of a nylon nonwoven fabric and a reinforcing layer of
fiberglass scrim. This composite fabric is lightweight, strong, and
flexible, and demonstrates good moisture stability.
In one application, the composite fabric of this invention may be
used as a moisture-stable carpet backing for a carpet made from
nylon tufts bonded to a reinforced nylon strand. Such a carpet is
described in co-pending U.S. patent application Ser. No.
08/017,162, filed Feb. 22, 1993, the disclosure of which is hereby
incorporated by reference. A carpet having a backing composed of
the composite fabric of this invention would offer other advantages
in addition to being moisture-stable. For instance, such a carpet
could easily be recycled, since it would consist only of nylon and
nylon-melt compatible components. In conventional carpets, many
different components, such as nylon, latex and polypropylene, must
first be separated with great difficulty before the nylon carpet
tufts can be depolymerized.
SUMMARY OF THE INVENTION
This invention provides a composite fabric comprising a first layer
of a nonwoven fabric comprising entangled, non-bonded nylon
filaments. Preferably, the weight of said fabric is in the range of
about 0.75 to about 6.00 ounces per square yard. The second layer
is a fiberglass scrim comprising an array of intersecting
continuous multifilament glass strands. The third layer is a
nonwoven fabric comprising entangled, non-bonded nylon filaments.
Preferably, the weight of this fabric is also in the range of about
0.75 to 6.00 ounces per square yard. The first layer of nonwoven
fabric is adhesively attached to the layer of fiber glass scrim at
the contact surface of said fabric and scrim. The second layer of
nonwoven fabric is adhesively attached to the fiberglass scrim at
the contact surface of said fabric and scrim.
Preferably, the fiberglass scrim is composed of an intersecting
array of at least 6 multifilament strands by 6 multifilament
strands per inch of scrim, wherein each strand has a denier of at
least 500 and a tensile break strength of at least 8 pounds. The
scrim may also include multifilament fiberglass strands crossing
over the intersecting array of multifilament strands in a
diagonal.
Preferably, the nylon filaments of the nonwoven layer of fabric are
hydro-entangled or needle-punched, and these filaments may be
continuous filaments or staple fiber.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to a composite fabric comprising a first
layer of a nonwoven nylon fabric, a reinforcing layer of fiberglass
scrim, and another layer of nonwoven nylon fabric. The nonwoven
nylon fabric is composed of entangled nylon filaments which are not
fused or bonded to each other.
The fiberglass scrim is an open network structure made of
continuous, multifilament, fiberglass yarn strands. This open
network may or may not be woven. The scrim may be manufactured by
techniques known in the trade, such as those described in U.S. Pat.
Nos. 3,728,195, 4,030,168, and 4,762,744, the disclosures of which
are hereby incorporated by reference. Preferably, the fiberglass
scrim contains at least 6 multifilament strands per inch evenly
spaced in the "machine direction" (MD) and at least 6 multifilament
strands evenly spaced in the "cross direction" (XD). By the term,
"machine direction", it is meant the length direction of the
fabric, i.e., the direction in which the scrim is being produced by
the machine. By the term, "cross direction" it is meant the width
direction of the fabric, i.e., perpendicular to the direction in
which the fabric is being produced by the machine. It is important
that the strands be evenly spaced so there is not an excessive
length of strand between crossing support strands, because this
length may be more likely to buckle when a compressive force is
applied. An array having a free span of strand no greater than 1/4
inch is preferred when using conventional scrims. If heavier
strands are used in the scrim, then the free span can be greater
than 1/4 inch.
Preferably, there are at least 6 strands per inch by 6 strands per
inch of multifilament yarns making up the scrim array, and the
scrim has a tensile break strength in both the MD and XD of 45
lbs/inch. The preferred weight of the strands in the fiberglass
scrim is at least 500 denier, and each strand in the MD and XD
direction has a break strength of about 8 pounds. The following
table illustrates the tensile break strength properties of
different fiberglass scrims having an intersecting array of 6
strands in the MD and 6 strands in the XD.
______________________________________ Strands Break Strength Break
Strength Denier Per Inch Per Strand Per Inch
______________________________________ 2000 6 .times. 6 32 lbs. 192
lbs./inch 1000 6 .times. 6 16 lbs. 96 lbs./inch 500 6 .times. 6 8
lbs. 48 lbs./inch 250 6 .times. 6 4 lbs. 24 lbs./inch
______________________________________
If the composite fabric is intended for use as a backing fabric in
the above-mentioned tuftstring carpet assembly, then the
intersecting array is preferably 8 strands in the MD .times.8
strands in the XD, and the XD strands are preferably 2000 denier
with a break strength of about 32 lbs. This is necessary, because
the backing fabric is not strengthened by the elongated pile
articles (tuftstrings) that run in the MD. The yarns in the MD may
have the same or different denier and break strength than the XD
strands. The use of such a strong backing fabric will result in a
tuftstring carpet structure that exceeds the federal requirement of
a 100 lb. standardized grab strength (4" wide sample clamped by a
1" wide clamp) in the MD and XD. The tuftstring contributes
substantial strength to the assembled carpet in the MD, but at the
same time, the tuftstring may weaken the strength of the scrim in
the XD if ultrasonic bonding is used. This can be compensated for
by adjusting the relative amount of fiberglass in the MD and XD of
the composite fabric backing.
The fiberglass in the scrim is effective, because of its good
tensile strength, thermal dimensional stability and moisture
dimensional stability. In the laminate, composite fabric of this
invention, the fiberglass easily overcomes expansion forces in the
nonwoven, unbonded nylon fabric. When the specified scrim weight is
used, it has also been found to be stiff enough to overcome the
weak shrinkage forces in the specified nonwoven, unbonded nylon
fabric.
With the scrim only containing yarns in the XD and MD directions,
the composite fabric may not have enough diagonal stability for
some applications. The structure can be made stable in the diagonal
directions by adding fiberglass strands to the scrim in the
diagonal directions. If the composite fabric is used as a
tuftstring carpet backing, the diagonal strength requirements are
less than the XD and MD requirements, so a lower denier strand
could be used for the diagonal strands than for the XD and MD
strands.
Each of the nonwoven nylon fabrics may be made by a conventional
hydro-entanglement process as described in U.S. Pat. No. 3,485,706,
the disclosure of which is hereby incorporated by reference, or by
a conventional needle-punching process. The preferred weight of
each nonwoven nylon fabric is 1 to 2 oz./sq. yd., although up to 4
oz./sq. yd. may be useful for some applications. Preferably, the
hydro-entanglement process is used to manufacture the fabrics,
since it is possible to make a much lower weight fabric having good
uniformity with this process. Generally, the lowest weight
conventional needle-punched layer possible is about 3.5 to 4
oz./sq. yd., and this process is more expensive than
hydro-entanglement. In this invention, the weight of the nonwoven
nylon fabric only needs to be 1 to 2 oz./sq. yd. in order to
produce a useful lightweight, composite structure. Such a composite
structure is especially useful as a backing in a tuftstring carpet
assembly.
The nonwoven nylon layers are attached to the fiberglass scrim by
an adhesive applied to the surface of the scrim. The first layer of
nonwoven fabric is adhesively attached to the layer of fiber glass
scrim at the surface where the fabric and scrim are in contact. The
second layer of nonwoven fabric is adhesively attached to the layer
of fiber glass scrim at the surface where this fabric and scrim are
in contact. The scrim is coated with a thermoplastic adhesive which
is compatible with the fiberglass strands and the nylon nonwoven
fabrics. Suitable adhesives include, for example, modified acrylic
resins such as a methyl methacrylate and ethyl acrylate
cross-linked composition, styrene-butadiene (SBR) latex, polyvinyl
chlorides, polyurethanes, and polyolefins. Hot melt adhesives may
also be used. The scrim may be coated with the adhesive in any
suitable manner such as spraying, dipping, or kiss-roll coating.
The adhesive may also be applied in the form of a preferred web of
thermoplastic adhesive, such as a 0.6 oz./sq. yd. fusible web of
polyester and polyolefin, available as "Sharenet", from Applied
Extrusion Technology of Wilmington, Del. The adhesive web may be in
addition to applying adhesive to the scrim and may be placed
between one of the layers of nonwoven and the scrim. The second
layer of nonwoven may be joined to the scrim and adhesively joined
to the adhesive web and the first nonwoven layer where the contact
is made between the strands of the scrim. The adhesive of the web
remains on the surface where it contacts the nonwoven layers and
does not penetrate to the opposite surfaces of the nonwoven
layers.
The adhesive process is preferred since it is cost effective and
works with very low weight nonwoven layers. When a
hydro-entanglement attachment process is used with low weight
nonwoven fabric layers, an open structure results where the jets
displace all the filaments at the openings in the scrim. This
results in poor or no bonding between the the scrim and nonwoven
nylon fabric when the backing is attached to another substrate,
such as a tuftstring, which crosses the open area. Although using a
heavier denier layer of nonwoven fabric may eliminate openings in
the layer, the hydroentanglement attachment process also does not
firmly attach the scrim to the nonwoven layers so the scrim is less
effective in resisting expansion and shrinkage of the nonwoven
layers.
It is important that the nonwoven nylon layers comprising the
composite fabric have an unbonded structure, such as a
hydro-entangled structure, at least between the scrim strands, so
the individual nylon filaments comprising the nylon layers can be
mobile in the composite fabric. The nylon filaments at the surface
of the fabric layer contacting the scrim may be bonded together due
to the adhesive on the strands of the scrim. However, in order to
avoid bonding of the nylon filaments between the scrim strands, the
adhesive should not extend substantially beyond the width of the
strands in the scrim.
It has been discovered that a spunbonded, nonwoven nylon fabric,
such as "Cerex" made by FiberWeb North America, Inc. of
Simpsonville, S.C. may be used to produce a strong lightweight
composite "Cerex"/Fiberglass/"Cerex" material, but not a stable
structure that remains flat when subjected to repeated wettings and
dryings. Rather, after repeated wettings and dryings, the
spunbonded nylon shrinks to area dimensions less than the
dimensions it had before it was bonded to the fiberglass scrim.
Since the spunbonded nylon shrinks and the fiberglass does not, and
the fiberglass scrim has limited ability to resist these shrinkage
forces, the "Cerex"/Fiberglass/"Cerex" composite buckles, puckers,
and wrinkles. It is believed that since the nonwoven nylon fabric
is bonded, the individual filaments are fixedly connected at every
intersection and the filaments are predominantly short and straight
between intersections. Therefore, shrinkage of individual filaments
causes shrinkage of the entire nonwoven nylon fabric, and
substantial shrinkage forces are developed that cannot be overcome
by the buckling stiffness of the glass fiber strands.
In the case of the composite fabric of this invention, the
unbonded, nonwoven, nylon filaments also undergo shrinkage with
repeated wetting and drying, but without a detrimental effect on
the composite structure. It is believed that since individual
filaments are not fixedly connected to adjacent filaments, and
there are relatively long loopy lengths of filaments between
entanglement points, the filaments are individually moveable
without transmitting a substantial force to adjacent filaments.
Thus, the filaments do not act together to cause shrinkage of the
nonwoven fabric. No substantial shrinkage forces are developed that
overcome the buckling stiffness of the glass fiber strands, so the
composite fabric of the invention remains dimensionally stable with
changes in moisture and temperature. To insure the loopy lengths of
filaments are present in the fabrics during assembly with the
scrim, it is important that the fabric not be put under a tension
that may cause straightening of the filaments during assembly.
Preferably, a very low tension is exerted on the fabric at assembly
with the scrim. This will decrease the amount of shrinkage in the
assembled composite product.
The nonbonded, nonwoven nylon fabric also acts as a supportive
carrier and protective surface for the fiberglass scrim whose small
denier multifilaments may be damaged by direct contact in rough
handling. The nonbonded, nonwoven nylon fabric does not propagate
substantial forces on the final assembly due to moisture or thermal
influences that tend to change the geometry of nylon filaments in
the fabric. This is especially so when the preferred low weight,
nonbonded, nonwoven nylon fabrics of this invention are used. One
preferred low weight, nonbonded, nonwoven fabric that has been
found to be particularly effective is a hydroentangled fabric made
by the DuPont Co. of Wilmington, Del. under the registered
trademark "Sontara", where the filaments used are made of nylon 6
or nylon 6,6, or copolymers thereof. Such a fabric may or may not
be isotropic as this is not critical in this invention and may be
compensated for with the choice of fiberglass scrim used.
The invention is further illustrated by the following examples, but
these examples should not be construed as limiting the scope of the
invention.
TEST METHODS
Moisture Stability
A test was run with five different 40 cm .times.40 cm samples to
measure the expansion and shrinkage as the samples were exposed to
changing conditions of temperature and humidity. The test involved
evaluating the moisture of the samples at 10% RH and 100% RH at an
elevated temperature of 40.degree. C. to speed up the gain and loss
of moisture in the samples. Each sample had measurement marks
placed in the MD and XD about 30-35 cm long, and initial
measurements were made with the sample at ambient temperature and
humidity of about 27.degree. C. and 45% RH. It was also discovered
that the effects of moisture on a sample may be different after the
sample has been through one complete wet and dry cycle, so in most
cases the test results include two cycles of wet and dry. For the
wet cycle, the sample was submerged in a shallow pan of slowly
circulating water heated to 40.degree. C. and left for at least 24
hours. The sample was then removed from the water and quickly
measured while wet. For the dry cycle, the wet sample was placed on
a wire rack in an oven heated to 40 deg.degree. C. and left for at
least 24 hours. The sample was then removed from the oven and
quickly measured while dry. For more cycles, the dry sample was
submerged in the water again and the process repeated. Several
samples may have been placed in the water or oven at the same time
.
EXAMPLES
The following samples were made by two different laminating
methods. In some cases, the nylon nonwoven fabrics and scrim were
processed in three (3) to six (6) feet wide webs and led to a hot
nip where pressure was applied. In other cases, discrete sheets of
nylon nonwoven fabrics and scrim were placed together in a hot
press and laminated together. An amount of adhesive was used to
attach the surface filaments of the fabrics to the scrim without
passing through the fabrics to the side opposite the scrim. The
modified acrylic resin used in the following samples was a
cross-linked methyl methacrylate and ethyl acrylate composition.
The moisture stability of the samples was then measured in
accordance with the above Test Methods, and the results are
reported in Table 2. The numbers in Table 2 are the percentage
change in dimension relative to the sample dimensions at ambient
conditions.
Sample 1: one 1 oz/sq yd nylon "Sontara" fabric with no scrim.
Sample 2: 1 oz/sq yd nylon "Sontara" fabric; laminated to a 500
denier XD .times.1000 denier MD fiberglass scrim, 6.times.6 strands
to the inch, SBR latex (styrene butadiene resin) adhesive applied
to the scrim; laminated to a 1 oz/sq yd nylon "Sontara" fabric.
Sample 3: 1 oz/sq yd nylon "Sontara" fabric; laminated to a 500
denier XD .times.1000 denier MD fiberglass scrim, 6.times.6 strands
to the inch, "Rhoplex" water based acrylic resin adhesive,
available from Rohm and Hass Co., applied to the scrim by spraying;
laminated to a 1 oz/sq yd nylon "Sontara" fabric; all layers
laminated together in a hot press at 170.degree. C. under 5
psi.
Sample 4: 1 oz/sq yd nylon "Sontara" fabric; laminated to a 1000
denier XD .times.1000 denier MD fiberglass scrim, 8.times.8 strands
to the inch, modified acrylic resin adhesive applied to the scrim;
laminated to a 1 oz/sq yd nylon "Sontara" fabric.
Sample 5: 1 oz/sq yd nylon "Sontara" fabric; laminated to a 500
denier XD .times.1000 denier MD fiberglass scrim, 6.times.6 strands
to the inch, "Sharenet" resin adhesive mat, available from Applied
Extrusion Technology of Wilmington, Del., placed between the first
mat and the scrim; laminated to a 1 oz/sq yd nylon "Sontara"
fabric; all layers laminated together in a hot press at 170.degree.
C. under 5 psi.
Sample 6: one 1 oz/sq yd "Cerex" fabric with no scrim.
Sample 7: 1 oz/sq yd "Cerex" fabric; laminated to a 1000 denier XD
.times.1000 denier MD fiberglass scrim, 6.times.6 strands to the
inch, SBR latex (styrene butadiene resin) adhesive applied to the
scrim; laminated to a 1 oz/sq yd "Cerex" fabric.
Sample 8: 1 oz/sq yd "Cerex" fabric; laminated to a 500 denier XD
.times.1000 denier MD fiberglass scrim, 6.times.6 strands to the
inch, "Rhoplex" water based acrylic resin adhesive applied to the
scrim by spraying; laminated to a 1 oz/sq yd "Cerex" fabric; all
layers laminated together in a hot press at 170.degree. C. under 5
psi.
Sample 9: 1 oz/sq yd "Cerex" fabric; laminated to a 500 denier XD
.times.1000 denier MD fiberglass scrim, 6.times.6 strands to the
inch, "Sharenet" resin adhesive mat placed between the first fabric
and the scrim; laminated to a 1 oz/sq yd "Cerex" fabric; all layers
laminated together in a hot press at 170.degree. C. under 5
psi.
Sample 10: 1 oz/sq yd nylon "Sontara" fabric; laminated to a 500
denier XD .times.1000 denier MD fiberglass scrim, 6.times.6 strands
to the inch; laminated to a 1 oz/sq yd nylon "Sontara" fabric; all
layers ultrasonically bonded in one step by melt fusion of the two
fabrics to each other through the scrim.
TABLE 2 ______________________________________ MOISTURE STABILITY
(% CHANGES IN DIMENSION FROM AMBIENT) 40.degree. C./ 40.degree. C./
40.degree. C./ 40.degree. C./ 100RH 10RH 100RH 10RH SAMPLE DIR wet
dry wet dry TOT ______________________________________ 1 XD +10.4
+4.7 * +10.1 +8.4# 10.4 MD -0.7 -3.8 * -2.1 -6.9# 6.9 2 XD 0 +0.3
+0.3 +0.3 0.3 MD +0.3 --** +0.1 -0.6 0.9 3 XD +0.3 -0.3 +0.3 -0.3
0.6 MD 0 0 0 0 0 4 XD 0 0 0 0 0 MD 0 -0.3 0 -0.6 0.6 5 XD 0 0 0
-0.3 0.3 MD 0 0 0 0 0 6 XD +3.2 -2.2 +3.0 -2.2 5.4 MD -2.0 -7.2
-1.9 -6.9 7.2 7 XD +0.3 -1.7 +0.4 -1.4 2.1 MD +0.3 -4.0 +0.3 -3.7
4.3 8 XD 0 -3.0 +0.3 -2.9 3.3 MD -0.3 -0.9 0 -1.2 1.2 9 XD 0 -1.4 0
-2.1 2.1 MD -0.2 -0.8 -0.3 -0.8 0.8 10 XD 0 0 * 0 +0.3 * 0.3 MD 0
-1.8 * 0 -2.4 * 2.4 ______________________________________ NOTE: *
25.degree. C./15RH #36.degree. C./13RH **Incorrect measurements
taken; correct measurements not available.
These slight variations in the dry part of the cycle are considered
insignificant for comparisons between the samples.
The stability criteria for the composite fabric of this invention
is that the XD and MD dimensions should not change more than 1%
under the conditions tested. A preferred form of the invention has
dimensional changes no greater than 0.5% which can be successfully
used as a backing for a tuftstring carpet as described above. A
sample is considered to pass if the total dimensional change from
maximum shrinkage to maximum expansion in any one direction is no
greater than 1.0%. On this basis, samples 2, 3, 4, and 5 passed;
samples 1, 6, 7, 8, 9, and 10 failed.
It was observed from the data for samples 3 and 5 that there was no
shrinkage of the samples in the MD, even though in sample 1, the
"Sontara" had a tendency to shrink a large amount in the MD, which
was reflected in the other passing samples 2 and 4. It is believed
that since samples 2 and 4 were made in a continuous process where
some MD tension was applied to the "Sontara" and samples 3 and 5
were made in a batch process with no tension, this resulted in a
higher shrinkage force in the pretensioned samples. Better results
can be obtained if the tension in the nonwoven is low or near zero
when it is joined with the scrim.
In sample 10, a lamination as in sample 3 was made, but the
attachment was by ultrasonic bonding of the two mats to each other
through the openings in the scrim instead of adhesive applied to
the scrim. This resulted in many bonds between the filaments of the
mats and produced a stiffer laminate. It behaved like the
spunbonded laminate of samples 7, 8, and 9 that had the filaments
in the nonwoven bonded to one another; the expansion of sample 10
was contained, but shrinkage in the MD was excessive at 2.4%.
* * * * *